Patent US1675160A successfully refreshed from Google Patents.
Patent US2677965A successfully refreshed from Google Patents.
Patent US2470716A successfully refreshed from Google Patents.
Patent US2041600A successfully refreshed from Google Patents.
US2041600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio system
Assignee: AT&T Inc
•
Filing: 1934-04-05
•
Granted: 1936-05-19
•
Expires: 1954-04-05
Abstract
No abstract record available.
Inventors
- 👤 Harald T Friis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:01
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/30; H01Q3/32
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1939-05-19 | 1939-11-18 | 1940-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1943-05-19 | 1943-11-18 | 1944-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1947-05-19 | 1947-11-18 | 1948-05-19 | $7700.00 | Window Closed / Lapsed |